14 FLORA INDICA. tural ordete of plants. Unfortunately, 19 tx>tany, as in every otheu hranch of natural science, no progress can b£ made in the study of the vital phenomena except the observer have a previous accurate acquaintance with the various modifications under which the individual organs of plants appear in the dif- ferent natural orders, and such an appreciation of the /com- parative value, structural and nforphological, of these modifi- cations, as can only be obtained by a careful study of the affi- nities of their genera and species.*Ignorance of these general laws leads to misinterpretation of the phenomena investigated by the physiologist, and to that confusion of ideas which is so conspicuous in the writings of some of the astute physiolo- gical observers of the dayy The modern system of botanical instruction attempts far too much in a very limited space of time, and sends the ntu- dent forth so insufficiently grcmjxled in any branch of the science, that -he is unprepared fox the difficulties which he encounters, let' his desire to progress be ever so great. The history of botanical discovery, and the philosophy of its ad- vance, form instructive chapters for the student in any de- partment of natural science. In Professor Whrorell's * His- tory of the Inducti\e Sciences/ the subject is ably sketched for the information of the general reader; and it is there shown that the most important contributions to the pro£re»s of the science have been purely physiological questions, in- vestigated with consummate judgment by our most eminent systematists. "We owe to Linnseus the establishment of the doctrine of the sexuality of plants; and we find by the writ- ings of the same great naturalist, that besides foreseeing many physiological discoveries, he preceded Goethe in the discovery of morphology, a doctrine which, more than any other, has tended to advance scientific botany* A third great discovery, that of the nature of the ovule, and the relation of the pollen- tube to the ovary, received its principal illustration at the hands of Brown, oiir chief systematic, and of Brouguiart, also n practised botanist.